Device with a reactor in which process gases different from one another can be fed in during process steps different from one another and methods in which process gases different from one another are fed into a reactor during process steps different from one another are known from the prior art. For instance, U.S. Pat. No. 7,647,886 B2 has a process chamber into which process gases different from one another are fed in from several gas sources in process steps different from one another. The process gases pass through a gas inlet member into the process chamber. A substrate to be coated is located in the process chamber on a heated susceptor. The processes gases are broken down, particularly pyrolytically, and form a coating and an exhaust gas. The exhaust gas passes through an exhaust gas line from the process chamber and is treated in a first exhaust gas device, which is an exhaust gas treatment device. When a second process gas is used, for example a treatment gas with which coatings that are parasitic to the process gas are to be etched off of the walls, a second exhaust gas device is used which is also an exhaust gas treatment device. The two exhaust gas treatment devices have treatment members that are different from one another in which a respective exhaust gas or reaction product is filtered out.
A device having two exhaust gas devices is described in US 2007/0207625 A1. Each of the two exhaust gas devices has a pump and a gas treatment in the form of a scrubber. In this device, flushing gases can be fed into the two exhaust gas devices.
A device and method are known from US 2012/0304930 A1 in which two exhaust gas devices arranged parallel to each other are used, each of which has a cooling trap and a pressure control valve.
An arrangement of exhaust gas treatment devices having two pumps and a common treatment device is also described by US 2013/0237063 A1.
U.S. Pat. No. 4,817,557 describes a process chamber arrangement for executing a CVD process in which a ballast gas can be fed in through an exhaust gas line via a mass flow controller with which the total pressure in the process chamber can be varied or controlled while the suction power of the pump arrangement is maintained at a set value.